Embodiments of the present specification relate to a power generation system and, more particularly to a method and a control sub-system for operating a power generation system such that a steam-carbon ratio in a fuel-cell is maintained above a threshold steam-carbon ratio value.
A fuel-cell is an electrochemical energy conversion device that has demonstrated potential in terms of higher efficiency and lower pollution in comparison to that of coal and/or diesel based power generation systems. Common types of the fuel-cell include a polymer electrolyte membrane fuel-cell, a direct methanol fuel-cell, an alkaline fuel-cell, a phosphoric acid fuel-cell, a molten carbonate fuel-cell, and a solid oxide fuel-cell (SOFC). Fuel-cells, such as solid oxide fuel-cells (SOFCs) may operate in large-scale power generation systems to satisfy industrial and municipal needs. The fuel-cell typically includes an anode, a cathode, and an electrolyte disposed between the anode and the cathode. Typically, the fuel-cell generates electrical power based on a chemical reaction between hydrogen and steam received at the anode and oxygen/air received at the cathode.
In a traditional power generation system that employs the fuel-cell, the anode of the fuel-cell may get damaged and degraded due to deposition of carbon on the anode. As will be appreciated, during operation, the fuel-cell generates water or steam as an exhaust. The amount of water or steam generated by the fuel-cell is proportional to an amount of the electrical current generated by the fuel-cell. Moreover, in the traditional power generation systems, in certain situations, including, but not limited to, a loss or disconnection of an external load from the power generation system, a premature shut-down of the power generation system, a scheduled shut-down of the power generation system, or an abnormality of one or more internal components of the power generation system, the electrical current generated by the fuel-cell decreases. Consequently, the amount of water or steam generated by the fuel-cell may also decrease. Accordingly, in these instances, when the water or steam generated by the fuel-cell reduces below a certain amount, the amount of carbon deposited on the anode of the fuel-cell increases leading to the degradation of the anode. This degradation of the anode further causes reduction in the lifetime of the fuel-cell and reduction in an efficiency of the traditional power generation systems.